DE102020120231A1 - Gravity cup with an inner bag that can be used as an option - Google Patents

Abstract

A flow cup (17) for a spray gun (1) is described, which has a material outlet (12) which is designed for direct and/or indirect connection to the spray gun (1), the flow cup (17) having a material container (19 ) and a lid arrangement (20) which releasably closes the material container (19), an inner bag (18) being arranged in the material container (19) and being able to be filled with coating material. The flow cup (17) is designed in such a way that it can be filled with coating material with or without the inner bag (18) and used to release the coating material via the material outlet (12) to the spray gun (1). 18) and a gravity cup arrangement (11).

Description

The invention relates to a flow cup for a spray gun, which has a material outlet which is designed for direct and/or indirect connection to the spray gun, the flow cup having a material container and a lid arrangement that releasably closes the material container, with an inner bag being arranged in the material container and having Coating material can be filled, the filled in the inner bag coating material can be supplied via the material outlet of the spray gun.

Furthermore, the invention relates to an inner bag for a gravity cup and a gravity cup arrangement with a gravity cup and an inner bag.

A flow cup described above is, for example, from EP 2 027 931 B1 become known, which has a paint container and a cover that can be placed on the paint container. The gravity cup includes a connection part for connecting the gravity cup to a spray gun. the EP 2 027 931 B1 mentions a variant in which the gravity cup is equipped with a liner (flexible inner bag). As an alternative to the variant with a liner, the font describes versions without a liner and e.g. B. with a ventilation valve in the bottom of the paint container.

Both gravity cups that are designed to be used with an inner bag and gravity cups that are designed to be used without an inner bag have their specific advantages depending on the coating task and properties of the coating material. A company, e.g. A paint shop, for example, must decide which flow cup system (with or without an inner bag) to choose, taking into account the spectrum of its coating tasks and the respective preferences of the operational users. Alternatively, the company can procure both gravity cup systems. However, he then has to accept double procurement, double stockpiling, etc.

The object of the invention is to provide a flow cup or flow cup arrangement that can be used flexibly.

According to the invention, the object is achieved by a flow cup having the features of claim 1.

The gravity cup according to the invention is characterized in that it can be filled with coating material with or without the inner bag and can be used with the coating material being released via the material outlet to the spray gun.

Thanks to the invention, a company no longer has to decide in advance on one type of flow cup or procure and stock both types. Immediately before carrying out a coating task, the end user can decide whether to use the flow cup according to the invention with or without an inner bag. This is made possible in particular by the flow cup according to the invention being fully functional without an inner bag. It can be filled with coating material, especially paint materials such as top coat, clear coat, filler, etc. Apart from a desired escape via the material outlet, escape of the coating material from the flow cup is avoided, i. H. the flow cup and in particular the wall of the material container is liquid-tight and solvent-resistant. In particular, there is also a device that enables pressure equalization for the interior of the material container when the coating material is discharged via the material outlet.

Against this background, an exemplary embodiment is particularly preferred in which the gravity cup has a ventilation device that includes at least one ventilation opening, via which, when using the gravity cup with and without an inner bag, pressure can be equalized for the interior of the material container when coating material is poured out of the gravity cup via the material outlet. In addition, at least in one operating state, the ventilation device can prevent liquid from escaping from the interior of the material container through the ventilation opening.

For example, the gravity cup can be equipped with an aeration device that permanently prevents fluid (gas and liquid) from escaping from the gravity cup, but at the same time fluid can enter due to the formation of a vacuum inside the gravity cup. For this purpose, the ventilation device z. B. a beak valve, diaphragm valve, etc. on.

Alternatively, the gravity cup can be equipped with an aeration device that permanently prevents liquid from escaping from the gravity cup, but at the same time allows gas to enter. This can preferably be realized by using a semi-permeable membrane.

In a particularly preferred embodiment, this is ventilation device to a manually operable ventilation device or ventilation valve. The ventilation valve preferably has a closure element which can be moved by the user between an open position and a closed position. This type of ventilation valve is characterized by a high level of functional reliability. The ventilation valve can be designed as a rotary, tilting, sliding, rotating valve, etc.

An embodiment of the flow cup with an aeration device in the form of a plug-in valve, which is characterized by a particularly high level of functional reliability and a robust design, is particularly preferred.

The ventilation device, in particular the plug-in valve, is particularly advantageous in that it is designed in such a way that a closure element, e.g. B. in the form of a cap, can be assembled or disassembled by the user as needed. When using the flow cup with inner bag, the closure element is not required. If the gravity cup is delivered with a preassembled closure element, it can be dismantled before using the gravity cup with inner bag (e.g. if the gravity cup is configured as an upside-down gravity cup with a ventilation device on the container side). If the flow cup is delivered without a pre-assembled closure element, the closure element may not be able to be assembled at all. In both cases, any contamination or other impairment of the closure element is avoided when using the gravity cup with inner bag. The closure element can later be used with the gravity cup already used without an inner bag or with another gravity cup.

The ventilation device is preferably arranged on the cover arrangement of the flow cup, with the material outlet being provided, for example, opposite on the bottom of the material container.

Alternatively and also preferably, the ventilation device is provided on the material container and in particular on the bottom of the material container. In this case, a variant is preferred in which the cover arrangement is provided with the material outlet.

In a further variant of the flow cup according to the invention, the ventilation device and the material outlet are arranged on the cover arrangement.

In order to be able to ensure a functionally reliable positioning of the inner bag in the material container without additional holding means, in a particularly preferred embodiment the detachable connection between the material container and the lid arrangement is designed in such a way that when the flow cup with inner bag is used, the inner bag can be clamped between the material container and the lid arrangement.

Alternatively or additionally, the detachable connection between the material container and the lid arrangement is designed in such a way that the connection is fluid-tight when the flow cup is used with or without an inner bag. This reliably prevents the coating material from escaping between the material container and the lid arrangement when working with the flow cup, regardless of whether an inner bag is used. In addition, the fluid-tight design of the connection also allows coating material to be stored in the flow cup for a longer period of time, without it e.g. B. dries up or is contaminated by penetrating substances.

In particular, the connection between the material container and the lid arrangement is designed in such a way that the connection is fluid-tight both with an inner bag clamped between the material container and the lid arrangement and without the inner bag with direct contact between the material container and the lid arrangement. In order for the connection to be fluid-tight when used without an inner bag, no replacement component, such as e.g. B. an annular sealing member can be used instead of the inner bag.

In a particularly preferred embodiment, the detachable connection between the material container and the lid arrangement is (additionally) designed in such a way that the lid arrangement is fastened to the material container with sufficient holding force when the flow cup is used, with and without the inner bag.

A sufficient holding force is considered to be, for example, a holding force that holds the lid arrangement on the material container when an overpressure of at least up to 0.2 bar is present inside the gravity cup. Such overpressure can occur when coating material is stored in the closed gravity cup due to temperature fluctuations and solvent vapors.

In addition, the holding force should be large enough to prevent the connection from being loosened by pivoting or tilting the flow cup filled with coating material, which is connected to the spray gun either only via the material container or via the cover arrangement.

Preferably, the fluid-tight seal between the lid assembly and the material container is achieved by an axial and/or radial seal when using the gravity cup with an inner bag and by an axial and/or radial seal when using the gravity cup without an inner bag. In particular, various designs are conceivable and technically feasible.

In the case of an insert with an inner bag, a radial seal can be provided and without an inner bag an axial seal. As an alternative to the radial/axial configuration, the connection can be implemented in such a way that a radial/radial configuration, an axial/radial configuration or an axial/axial configuration results.

Due to the high functional reliability, an exemplary embodiment is particularly preferred in which the connection is designed such that the fluid-tight seal results from an axial and radial seal when using the flow cup with an inner bag and from an axial and radial seal when using the flow cup without an inner bag.

In the case of a particularly preferred exemplary embodiment, the full functional capability of the connection of the lid arrangement with the material container, with and without an inner bag, is achieved by a two-position solution. The connection between the lid arrangement and the material container is designed in such a way that the lid arrangement and the material container are connected to one another in a fluid-tight manner in a first position when the inner bag is clamped between them, and are connected to one another in a fluid-tight manner in a second position if no inner bag is clamped between them . The two positions differ from one another, for example, by the axial position and/or the rotational position of the cover arrangement and material container.

For the functionally reliable realization of radial seals with and without an inner bag, a variant of the invention is preferred in which the connection between the lid arrangement and material container is designed in such a way that when using the flow cup with an inner bag, the inner bag is clamped in a radial annular gap between the lid arrangement and the screw lid. When using the flow cup without an inner bag, the lid arrangement and the material container are in direct radial contact with one another in the area of the radial annular gap.

In a modified exemplary embodiment, when using the flow cup without an inner bag, the lid arrangement and the material container can be spaced apart from one another in the area of the radial annular gap. When using the flow cup without an inner bag, the seal is then made at a different point (axially and/or radially).

However, a variant is particularly preferred in which the lid arrangement and the material container are already in direct contact with one another in the first position in the area of the radial annular gap, even if no inner bag is used. In this way, during the transition from the first position to the second position, a radial pretension, in particular a spreading of the material container, is achieved.

For the functionally reliable realization of axial seals with and without an inner bag, a variant of the invention is preferred in which the connection between the lid arrangement and the material container is designed in such a way that when using the flow cup with an inner bag, the inner bag is clamped in an axial annular gap between the lid arrangement and the screw lid. When using the flow cup without an inner bag, the lid arrangement and the material container are in direct axial contact with one another in the area of the axial annular gap.

In a modified exemplary embodiment, when using the flow cup without an inner bag, the lid arrangement and the material container can be spaced apart from one another in the area of the axial annular gap. When using the flow cup without an inner bag, the sealing takes place at a different point (axially and/or radially) in this exemplary embodiment.

The inner bag is preferably axially clamped at a peripheral edge of the inner bag, which is formed on an open end face of the inner bag. An optionally provided clamping of the inner bag in the radial direction preferably takes place below the edge on a peripheral wall of the inner bag, which extends away from the edge.

Production engineering and stability advantages result from the fact that the cover arrangement is provided with a receiving groove for an edge area of the material container, with a central area of the cover arrangement adjoining the receiving groove.

Thanks to the receiving groove, the edge area of the material container connected to the lid arrangement (possibly including part of the inner bag) is stably enclosed on the inside and outside. Sealing preferably takes place with and without an inner bag insert between the lid arrangement and the material container at the base of the receiving groove (axial seal) and/or on the outside of the inner leg of the receiving groove (radial sealing).

In a preferred exemplary embodiment, a central area of the cover arrangement is designed as a continuation of at least a predominant part of an inner leg of the receiving groove. The design of the inner leg brings with it considerable manufacturing advantages. Components of flow cups are advantageously produced from plastic by an injection molding process. With regard to the plastic injection molding process, the variant of the invention is characterized in that the flow of liquid plastic is not divided at the transition from the central area of the cover arrangement to the receiving groove when the injection mold is being filled. Thanks to the invention, the area that is particularly sensitive to the functional reliability of the cover arrangement, namely the receiving groove, can be formed by a uniform (unbranched) flow of liquid plastic coming from the central area. This ensures that the injection molding tool is quickly, evenly and completely filled in this particularly critical edge area of the cover arrangement. As a result, the cycle times and also the wall thicknesses of the cover arrangement can be reduced without functional losses, which in turn leads to overall cost and material savings.

Regardless of the manufacturing process, the variant of the invention leads to an increase in functional reliability or allows a reduction in wall thickness and thus material savings. Since the inner leg of the receiving groove is not designed to be free-standing, but rather its end is connected to the central area of the cover arrangement, the inner leg is supported or stiffened by the central area, which in turn allows the wall thickness to be reduced while maintaining or even increasing rigidity.

In order to achieve the manufacturing and stability-related advantages, the central area does not have to be attached to the end of the inner leg (even if this is particularly preferred). Although the advantages of the invention result in a reduced degree, but still to a considerable extent, if a major part of the inner leg, z. B. more than 50%, preferably more than 75%, more preferably 95% of the total length of the inner leg (distance from the bottom of the groove to the outer edge of the inner leg) is designed as a continuation of the central area. i.e. conversely, that less than 50%, preferably less than 25%, more preferably 5% of the total length of the inner leg is designed as a free-standing or protruding collar, rib, bead, lip, etc.

In the case of a particularly preferred embodiment, the central region of the cover arrangement borders the receiving groove with a ring section which extends at least almost perpendicularly to the receiving groove. This constructive measure reinforces the explained supporting effect of the inner leg through the central area.

Preferably, the at least almost vertical ring section is followed by a ring section of the central area, which runs at least almost parallel to the inner leg in such a way that a further groove is formed, but which is open in the opposite direction of the receiving groove. The further groove forms a compensating ring groove, the dimensioning of which allows the desired support or rigidity of the inner leg to be defined.

For example, the connection between the lid arrangement and the material container can be designed as a snap or snap-in connection. In this exemplary embodiment, it can be used with and without a clamped-in inner bag in that the lid arrangement can be fixed in two axial locking positions on the material container. In the first locking position, the distance between the lid arrangement and the material container is large enough for the inner bag to be clamped at least axially between them. In the second position (for use without an inner bag), the lid arrangement and the material container are, for example, directly in contact with one another.

A connection can be designed in a surprisingly simple and robust manner that is fluid-tight both with and without a clamped inner bag, in that the connection between the lid arrangement and the material container is designed as a screw connection, in particular as a multi-threaded screw connection.

In a first rotational position, the distance between the lid arrangement and the material container is so large that the inner bag can be clamped at least axially between them. In a second rotational position (for use without an inner bag), the lid arrangement and the material container are in direct contact with one another, for example.

An inner bag for a flow cup and its manufacturing method are also considered to be independently inventive, the inner bag having a peripheral edge on one open end, from which a peripheral wall leads away, which is preferably closed on the opposite end or has an outlet extension.

For example, the edge has a wall thickness that is a multiple of the wall thickness of the peripheral wall. The wall thickness of the rim is preferably 0.4 mm to 0.7 mm, in particular approximately 0.5 mm, and the wall thickness of the peripheral wall is 0.1 mm to 0.3 mm, in particular approximately 0.2 mm.

The rim of the inner bag may be provided with one or more beads, lips, ribs, etc. to improve the seal when clamped between the lid assembly and the material container. It can also have one or more positioning depressions and/or be shaped in the shape of an angle profile.

Preferably, the inner bag is rotationally symmetrical to a longitudinal axis that extends along the peripheral wall. It preferably has a circular cross section. However, square, other polygonal, elliptical, etc. cross-sectional shapes are also conceivable and technically feasible.

The inner bag is preferably a flexibly collapsible inner bag. This is an advantage in particular in connection with a gravity cup as an upsidedown gravity cup (material outlet on the lid arrangement) with a ventilation device on the container side, since the inner bag has to contract when coating material escapes when used in such a gravity cup.

However, the inner bag preferably has sufficient inherent rigidity to nevertheless remain stable, i. H. collapsing or buckling without the influence of external forces.

It goes without saying that the inner bag is made of a fluid-tight, in particular solvent-resistant material, preferably plastic.

The inner bag is a mass product and is therefore produced in a deep-drawing process in the case of a particularly preferred exemplary embodiment.

Alternatively, the inner bag can be made in a blow molding process, in an injection molding process, e.g. B. with a hose system, by forming a (plastic) film under heating and pressure, etc. are produced.

In the case of a particularly preferred exemplary embodiment of an inner bag according to the invention, the inner bag is provided with at least one fold line along which the inner bag preferably buckles when there is negative pressure inside the inner bag or coating material escaping from the inside. Thanks to the crease line, the vacuum that is required for the inner bag to contract is reduced.

Alternatively or additionally, the crease line causes the inner bag to fold together in such a way that after folding or as much coating material as possible has flowed out of the inner bag, a smaller residual volume, e.g. B. between folds of the inner bag, remains in the inner bag.

The inner bag is particularly preferably provided with at least one fold line, which results from the shaping and/or weakening of the bag wall along the fold line.

The formation of the fold line or several fold lines can, for. B. immediately during or after the primary shaping or molding of the inner bag. Thus, when the inner bag is produced in a deep-drawing process, the mold into which the inner bag is drawn or pressed can be provided with a corresponding counter-mould to form at least one fold line. The same applies to the injection molding tools in an injection molding process.

However, it is also conceivable that the inner bag is initially formed without a crease line and is then provided with at least one crease line in a subsequent process step (preferably without reclamping or the like). For this purpose, the inner bag (possibly heated above the forming temperature of the plastic) can be pressurized, for example, by means of compressed air (which emerges from slits in the deep-drawing mold) or by means of thermal action (generated by heating wires, laser radiation, etc.).

The buckling line or several buckling lines can be introduced by changing the material (thermal, mechanical, chemical). For example, the wall thickness of the inner bag can be reduced along the fold line.

The buckling line or multiple buckling lines can also be introduced by reshaping. Furthermore, it is conceivable that the fold line(s) result from areas of the inner bag with different materials (composite inner bag).

The inner bag is preferably provided with at least one folding line which is closed in the form of a ring or runs in a spiral shape on the peripheral wall of the inner bag.

In the case of a particularly preferred exemplary embodiment, the inner bag is provided with a plurality of fold lines which are closed in the form of a ring and are at equal distances from one another or distances which increase or decrease in the longitudinal direction of the inner bag. A bellows-shaped or accordion-like inner bag preferably results.

In the case of a particularly preferred embodiment, the inner bag is provided with crossing fold lines. In particular, a variant of the inner bag is preferred, in which the inner bag is provided with a diamond-shaped fold line pattern in the manner of a tubular lantern.

A variant of the inner bag according to the invention, which is closed with a smooth bottom opposite the open end face or is provided with a funnel-like outlet extension, has proven itself in practice.

The object stated at the outset is also achieved by a gravity cup arrangement which comprises a gravity cup according to one of the exemplary embodiments explained above and below and an inner bag which can optionally be inserted therein according to one of the exemplary embodiments explained above and below.

In the case of a preferred embodiment of the gravity cup arrangement, the gravity cup can also be used without an exchangeable element for the inner bag when used without an inner bag.

However, the basic idea of the invention is also realized by a flow cup arrangement which comprises an exchangeable element, in particular a ring-shaped sealing element, which can be clamped between the lid arrangement and material container instead of the inner bag in order to use the flow cup without an inner bag.

• 1 eine Schnittdarstellung einer Spritzpistole mit einer Fließbecher-Anordnung gemäß einem ersten Ausführungsbeispiel der Erfindung,
• 2 eine Seitenansicht eines optional einsetzbaren Innenbeutels für den Fließbecher gemäß 1,
• 3 eine Seitenansicht eines ringförmigen Dichtelements, dass anstelle des Innenbeutels gemäß 2 in einem Fließbecher gemäß 1 eingesetzt werden kann,
• 4 eine Schnittdarstellung einer Fließbecher-Anordnung gemäß einem zweiten Ausführungsbeispiel der Erfindung,
• 5 eine Schnittdarstellung eines optional einsetzbaren Innenbeutels für den Fließbecher gemäß 4,
• 6 und 7 eine vergrößerte Schnittdarstellung der Verbindung von Deckelanordnung und Materialbehälter des Fließbechers gemäß den 1 und 4 mit und ohne eingespanntem Innenbeutel und
• 8 bis 10 schematische Seitenansichten zur Illustration von Varianten von optional einsetzbaren Innenbeuteln für den Fließbecher gemäß 4.

The invention is explained below using exemplary embodiments. The figures show:

• 1 a sectional view of a spray gun with a gravity cup arrangement according to a first embodiment of the invention,
• 2 a side view of an inner bag that can be used optionally for the flow cup according to FIG 1 ,
• 3 a side view of an annular sealing member that instead of the inner bag according to 2 in a flow cup according to 1 can be used
• 4 a sectional view of a flow cup arrangement according to a second embodiment of the invention,
• 5 according to FIG 4 ,
• 6 and 7 an enlarged sectional view of the connection between the lid assembly and the material container of the flow cup according to FIG 1 and 4 with and without a clamped inner bag and
• 8th until 10 schematic side views to illustrate variants of optionally insertable inner bags for the flow cup according to 4 .

In 1 a hand-held spray gun 1 for compressed air-assisted atomization and application of a free-flowing coating material is shown. The spray gun 1 can be designed, for example, as a so-called high-pressure, compliant or HVLP spray gun 1 . The spray gun 1 has a cup connection 2 and a nozzle head 3 at which the coating material supplied to the spray gun 1 via the cup connection 2 is atomized and emerges in the form of a spray jet.

Furthermore, the spray gun 1 comprises a handle 4, a trigger guard 5 for actuating a material needle 10 arranged inside the spray gun 1, an adjustment mechanism 6 for the stroke of the material needle (material quantity regulation), an air pressure adjustment device 7 (micrometer), a round/broad jet adjustment device 8 and a compressed air connection 9. B. an atomization and transport air on the one hand and a horn air for a wide beam formation on the other hand.

A flow cup arrangement 11 is connected to the cup connection 2 of the spray gun 1 by means of a material outlet designed as an outlet connection piece 12 . For this purpose, the outlet connector 12 is equipped with connection means in the manner of a bayonet lock, which include a clamping wedge element 13 that protrudes radially from the outlet connector 12 . The clamping wedge element 13 engages in a corresponding receiving groove 14 on the spray gun 1 . The outlet port 12 seals axially z. B. by means of its face 15 on the cup connection 2 (possibly via a clamping ring on the inner bag, 2 ) and/or radially with the help of two circumferential radial sealing lips 16 (in 1 hardly recognizable due to the proportions).

The gravity cup arrangement 11 comprises a gravity cup 17 and an inner bag 18 arranged in the gravity cup 17. The gravity cup 17 has a material container 19, on the bottom of which the outlet nozzle 12 is formed. Furthermore, the flow cup 17 comprises a lid arrangement closing the material container 19 in the form of a screw lid 20.

2 shows the inner bag 18 again on its own. It is made, for example, from plastic using a deep-drawing process.

An edge 21 of the inner bag 18 is clamped between the screw cap 20 and the material container 19 . From the rim 21 of the inner bag 18 extends a tubular peripheral wall 22 lining the interior of the material container 19 . On the opposite side of the edge 21, the peripheral wall 22 merges into a funnel-shaped outlet extension 23, which is adapted in terms of shape to the material passage of the outlet connector 12, lines it and is guided through it. The open end of the outlet extension 23 is provided with a circumferential clamping ring 24, by means of which the outlet extension 23 is fixed to the end face 15 of the outlet connector 12.

Out 1 It can be seen that inside the inner bag 18 a disk-shaped screen element 25 is inserted, through which the coating material has to pass before it can leave the inner bag 18 via the outlet nozzle 12 . As an alternative to the disk-shaped screen element 25, a tubular screen element can be used, which is inserted into the outlet socket 12 on the cup side and/or into the cup connection 2 on the pistol side.

The flow cup 17 according to 1 is designed as a standard gravity cup. It can be filled with coating material with or without the inner bag 18 and used to deliver the coating material to the spray gun 1 via the material outlet.

This is made possible in particular by the fact that the detachable connection 26 between the material container 19 and the screw cap 20 is designed in such a way that when the flow cup 17 with the inner bag 18 is used, the inner bag 18 is clamped between the material container 19 and the screw cap 20, with the screw cap 20 having a sufficient holding force is held on the material container 19 and the connection is fluid-tight. In addition, the connection is also secure and fluid-tight when using the flow cup 17 without an inner bag 18 .

In 3 an annular sealing element 27 is shown that can be mounted between the screw cap 20 and the material container 19 instead of the inner bag 18 in order to ensure that the connection between the screw cap 20 and the material container 19 is fluid-tight even without using the inner bag 18 . The sealing element 27 corresponds in shape to the edge section of the inner bag 18. It comprises an identically designed edge 28 and an in 3 downward protruding sealing collar 29.

However, it is advantageous for the flow cup 17 according to FIG 1 It is not necessary to mount the ring-shaped sealing element 27 in an application without an inner bag 18, since the screw cap 20 and the material container 19 are designed in such a way that they can also be connected directly to one another in a fluid-tight manner. The configuration of the connection 26 between the screw cap 20 and the material container 19 will later be described in more detail with reference to FIG 6 and 7 explained.

Out 1 it can be seen that a central area 30 of the screw cap 20 is provided with a ventilation device. The ventilation device is listed as plug valve 31. The plug valve 31 enables pressure equalization inside the gravity cup 17 when coating material flows out of the gravity cup 17 via the outlet connection 12 or the outlet extension 23 of the inner bag 18. The inner bag 18 does not have to contract with this gravity cup arrangement 11 when coating material is applied to the Pointed gun 1 is released.

The plug-in valve 31 has a manually operable closure element in the form of a closure cap 32, by means of which a ventilation opening 33 in the end wall 34 of the screw cap 20 can be closed. The closure cap 32 is slidable perpendicular to the end wall 34 between an open position and a closed position. In the open position, air can flow through the ventilation opening 33 into the interior of the gravity cup 17 . In the closed position, a sealing plug 35 on the sealing cap 32 closes the ventilation opening 33 so that neither air can enter the gravity cup 17 nor coating material can escape from the gravity cup 17 via the ventilation opening 33 .

The closure cap 32 can be assembled or disassembled by a user as required.

In 4 a second exemplary embodiment of a gravity cup arrangement 11 with a gravity cup 17 and an inner bag 18 arranged therein is shown. Overall, the flow cup 17 according to the second embodiment in contrast to the gravity cup 17 according to 1 designed as an upsidedown gravity cup. However, the screw connection 26 between the screw cap 20 and the material container 19, the plug-in valve 31 and the connection means on the outlet connection 12 are identical in construction to the corresponding components of the flow cup arrangement 11 according to FIG 1 executed.

In contrast to the first exemplary embodiment, the outlet socket 12 is arranged on the screw cap 20 and the plug-in valve 31 is arranged on the bottom 37 of the material container 19 . In the screw cap 20 is a sieve element receptacle 36 for a flat, disc-shaped sieve element (not shown) analogous to that in FIG 1 Screen element 25 shown is provided. As an alternative to a flat screen element, a tubular plug-in screen can be used, which can be fastened in the outlet socket 12 or in the cup connection 2 on the spray gun side.

In 4 the plug-in valve 31 is shown in a closed position. Before using the flow cup 17 with an inner bag 18, the piercing valve 31 must be opened so that air can flow into the space between the inner bag 18 and the material container 19, while the inner bag 18 contracts due to the escape of coating material from its interior. The closure cap 32 of the straightening valve 31 can also be completely dismantled beforehand.

Out 4 it can be seen that the bottom 37 is largely smooth on the inside with a concavity extending uniformly over the entire bottom 37 . This measure is particularly advantageous for an unimpeded and complete mixing of coating material in the flow cup 17 . The point of the concave base 37 that protrudes furthest inward due to the concavity has an offset of 1% to 4%, more precisely 2% to 3%, of the diameter of the base 37 relative to the outer edge region of the base 37 . In the embodiment shown, the diameter is z. B. d = 84.6 mm and the offset z. B. V = 2.0 mm.

A peripheral wall 38 of the material container 19 adjoins the concave bottom 37. The peripheral wall 38 is conical to the extent that the bottom 37 (despite the concavity) adjoins the peripheral wall 38 at an angle of greater than 90°. In the exemplary embodiments shown, there is an angle of approximately 92°.

The inner bag 18 is designed in the same way, which is again separately in 5 is shown. The inner bag 18 has, like the inner bag 18 according to 2 , An edge 21 by means of which it can be clamped between the screw cap 20 and the material container 19 . The peripheral wall 22 and the bottom 39 of the inner bag 18 are modeled after the material container 19 so that the inner bag 18 mounted inside largely completely lines the interior of the material container 19 and fits snugly against the walls of the material container 19 . The base 39 of the inner bag 18 is consequently also provided with an indentation extending uniformly over the entire base 39 . The peripheral wall 22 widens from the bottom 39 to the edge 21 (slightly) conically.

The flow cups 17 according to the first and second exemplary embodiment are preferably made of plastic in a plastic injection molding process, with the screw cap 20 and the material container 19 being formed in one piece apart from the closure cap 32 and the sieve elements 25 . Alternatively, the components can also be composed of several components, in particular the material outlet (outlet connector 12) can be produced as a separate component and inserted into the rest of the lid arrangement or the rest of the material container.

In the case of an exemplary embodiment that is not shown, one or more closure caps and/or one or more sieve elements can also be produced in one piece with the screw cap 20 or the material container 19 . For example, they can be attached at any point by tear-off webs, tabs, film hinges, etc., which can be severed in order to assemble the elements elsewhere.

The material containers 19 are made of polypropylene (PP), for example, and the screw caps 20 are made of high-density polyethylene (HDPE) or polypropylene (PP), for example. The closure cap 32 is also made of high-density polyethylene (HDPE) or polypropylene (PP), for example.

The flow cups 17 according to the invention are preferably extremely thin-walled products. The wall thickness of the material container 19 is in the range from 0.55 mm to 0.65 mm, specifically around 0.60 mm, and the wall thickness of the screw cap 20 is in the range from 0.75 mm to 0.85 mm, specifically 0 .80mm. The only exceptions are accumulations of material at local locations, e.g. B. for the formation of thread flanks, latching and gripping edges or on the outlet connector 12, in particular for the formation of the clamping wedge element 13.

Preferably, the screw cap 20 of the first embodiment and the material container 19 of the second embodiment are manufactured in an injection molding process in which the The injection point of the components is located as centrally as possible on the concave end wall (floor 37, central area 30). In order to make this possible, the ventilation device is arranged slightly off-centre. It is arranged with an offset of more than 5% but less than 10% of the diameter of the end wall 34 towards the middle of the end wall.

The injection point on the bottom 37 of the material container 19, which also corresponds to the point of maximum concavity, is located in 4 to the left of the ventilation opening 33 and is identified by the reference number 40 . In the exemplary embodiment shown, the offset between the eccentric ventilation opening 33 and the central injection point 40 is 5.50 mm, which corresponds to 6.50% for a diameter of the base 37 of 84.6 mm.

In the following, the screw connection 26 between the screw cap 20 and the material container 19 is based on the 6 and 7 described in detail. the 6 and 7 show an enlarged section of the structurally identical connection point of both the flow cup 17 according to FIG 1 as well as the flow cup 17 according to 4 .

In 6 the connection 26 is shown with the inner bag 18 clamped therebetween. The screw cap 20 and the material container 19 assume a first rotational position relative to one another. In 7 the connection 26 is shown without an inner bag 18 clamped therebetween. The screw cap 20 and the material container 19 assume a second rotational position relative to one another.

The edge area of the material container 19 is provided with a roll-up 41, which is stiffened by means of several radial transverse ribs. The transverse ribs end almost conclusively with the outer edge of the roll-up 41. The roll-up 41 has an outer leg, a middle connecting web and an inner leg. The inner leg merges into the peripheral wall 38 of the material container 19 . In the 6 and 7 1 is a section through a radial transverse rib integrally formed with the outer and inner legs and the center tie bar. The dashed lines in the 6 and 7 indicate the course of the outer and inner leg as well as the middle connecting bar. Four thread elements in the form of thread ridges 42 are provided on the outside of the outer leg of the roll-up 41 .

The edge area of the screw cap 20 has a receiving groove 43, which is also formed by an outer leg, a central connecting web and an inner leg. In the closed state of the flow cup 17, the receiving groove 43 encompasses the roll-up 41 in the edge area of the material container 19.

Inside the receiving groove 43, more precisely on the inside of the outer leg, four threaded ridges 44 are formed which, together with the threaded ridges 42 on the material container 19, form the multi-threaded screw connection 26. All four thread webs 44 begin approximately at the lower edge of the outer leg and open into the middle connecting web, which forms the bottom of the receiving groove 43 . The thread webs 44 therefore partially overlap in the circumferential direction, but are axially offset from one another in the overlapping area.

Both with and without the inner bag 18 clamped in, the fluid-tight seal between the screw cap 20 and the material container 19 is achieved by a circumferentially sealing, radial and axial contact inside the receiving groove 43. Specifically, the radial sealing occurs between the outside of the inner leg of the receiving groove 43 and the inside of the Inner leg of the roll-up 41 of the material container 19. When used with inner bag 18, the peripheral wall 22 of the inner bag 18 is clamped in a radial annular gap between the outside of the inner leg of the receiving groove 43 and the inside of the inner leg of the roll-up 41 of the material container 19.

The axial seal occurs between the top of the central connecting web of the roll-up 41 and the underside of the central connecting web of the receiving groove 43. When used without inner bag 18, the edge 21 of the inner bag 18 is in an axial annular gap between the top of the central connecting web of the roll-up 41 and the Clamped underside of the central connecting web of the receiving groove 43.

Examples are in the 6 and 7 three circumferential sealing ribs 47 are shown, which are formed on the outside of the inner leg of the receiving groove 43 and lead to a further reinforcement of the sealing effect. In addition, the sealing effect is improved in that the inner diameter of the material container 19 in the upper edge area is selected in such a way that the material container 19 is spread open when the screw cap 20 is installed, at least in the area of the roll-up 41, thus resulting in a particularly strong and sustained radial compression between the screw cap 20 and material container 19 results, which is reinforced when used with inner bag 18.

It goes without saying that, as an alternative or in addition, further sealing ribs, lips, beads can also be formed elsewhere in order to increase the sealing effect. Alternatively, for example only an axial or only a radial seal between the screw cap 20 and the material container 19 can also take place.

The central area 30 of the screw cap 20 is designed as a continuation of the inner leg of the receiving groove 43 . In the 6 and 7 only an outer portion of central region 30 is shown. In particular, the inner leg is followed by a first ring section, which extends at least almost perpendicularly to the receiving groove 43 . The ring section is followed by a second ring section, which runs at least almost parallel to the inner leg of the receiving groove 43 in such a way that a compensating ring groove 45 is formed, which is open in the opposite direction to the receiving groove 43 . By means of the compensating ring groove 45 z. B. manufacturing tolerances of the components are compensated, in particular to ensure the functionality, strength and tightness of the screw connection 26. In addition, a desired support or rigidity of the inner leg of the receiving groove 43 can be defined via the dimensioning of the compensating ring groove 45 .

Based on 8th until 10 Modified embodiments of the inner bag 18 for the gravity cup 17 are shown in accordance with FIG 4 explained. Advantageously, the inner bag 18 can be provided with at least one fold line 46, due to which the inner bag 18 contracts in the event of negative pressure in its interior or due to the coating material escaping from its interior, reducing the negative pressure and/or residual volume. The buckling line 46 or a plurality of buckling lines 46 can be introduced by changing the material (thermally, mechanically, chemically). For example, the wall thickness of the inner bag 18 can be reduced along the fold line 46 .

In 8th an inner bag 18 is shown which is provided with circumferentially closed fold lines 46 . Four buckling lines 46 are shown as an example, which are introduced by reshaping the peripheral wall 22, the specific form of the reshaping being slightly different in each case. In preferred variants, a plurality of fold lines 46 are provided on an inner bag 18 , but they are of the same type.

In 8th further fold lines 46 are merely outlined as a dashed line in order to clarify how fold lines 46 can be distributed along the peripheral wall 22 . In the example shown, the fold lines 46 are equidistantly spaced. However, the distances between the fold lines 46 can also be 8th increase or decrease from bottom to top.

In 9 an inner bag 18 is shown, which is provided with a spiral fold line 46 by way of example. Finally is in 10 a variant of an inner bag 18 is shown, the peripheral wall 22 is designed as a lampion-like tube due to crossing, diamond-shaped fold lines 46. The bottom, not shown, is closed and smooth, for example. The edge 21 of the inner bag 18 connected to the peripheral wall 22 is in 10 indicated only by dashed circles.

The edges 21 of all inner bags 18 shown have a wall thickness of 0.5 mm to 0.7 mm. The wall thickness of the peripheral walls 22 is 0.1 mm to 0.3 mm. All of the inner bags 18 shown are flexibly collapsible but have sufficient inherent rigidity to be stable, i. H. collapsing or buckling without the influence of external forces. The inner bags 18 are made of a fluid-tight, in particular solvent-resistant plastic. The inner bags are preferably made from a stretchable plastic film and/or from PE (e.g. LDPE) or PET.

Except for the inner bag 18 according to 10 All inner bags 18 shown are essentially rotationally symmetrical to their longitudinal axis.

The flow cup 17 according to the invention and the spray gun 1 equipped with it are suitable for atomizing and applying very different materials. A main area of application is automotive refinishing, in which top coat, filler and clear coat are used and which places very high demands on atomization and the properties of the spray jet. However, a large number of other materials can also be processed using the flow cup 17 and a possibly modified spray gun 1 . The decisive factor is that the materials are flowable and can be sprayed, at least to a certain extent.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 2027931 B1 [0003]

Claims (23)

Flow cup (17) for a spray gun (1), which has a material outlet (12) which is designed for direct and/or indirect connection to the spray gun (1), the flow cup (17) having a material container (19) and a den The material container (19) has a detachably closing lid arrangement (20), an inner bag (18) being arranged in the material container (19) and being able to be filled with coating material, the coating material filled into the inner bag (18) passing through the material outlet (12) of the spray gun ( 1), characterized in that the flow cup (17) is designed in such a way that it can be filled with coating material with or without the inner bag (18) and the coating material is released via the material outlet (12) to the spray gun (1) can be used. Gravity cup (17) after claim 1 , characterized in that the flow cup (17) has a ventilation device (31), in particular with a closure element (32) that can be installed and/or manually actuated by the user, the ventilation device (31) having at least one ventilation opening (33) via which when using the gravity cup (17) with and without an inner bag (18), the pressure inside the material container (19) can be equalized when coating material emerges from the gravity cup (17) via the material outlet (12), with the ventilation device (31) at least can prevent in an operating state that liquid can escape from the interior of the material container (19) through the ventilation opening (33). Gravity cup (17) according to one of the preceding claims, characterized in that the gravity cup (17) comprises a ventilation device (31) which is arranged on the cover arrangement (20). Flow cup (17) according to one of the preceding claims, characterized in that the detachable connection (26) between the material container (19) and lid arrangement (20) is designed in such a way that when the flow cup (17) with inner bag (18) is used, the inner bag ( 18) can be clamped between the material container (19) and the cover arrangement (20). Gravity cup (17) according to one of the preceding claims, characterized in that the detachable connection (26) between the material container (19) and lid arrangement (20) is designed in such a way that the connection (26) when using the gravity cup (17) with and without Inner bag (18) is fluid-tight. Gravity cup (17) according to one of the preceding claims, characterized in that the detachable connection (26) between the material container (19) and cover arrangement (20) is designed in such a way that the cover arrangement (20) when using the flow cup (17) with and without the inner bag (18) is attached to the material container (19) with sufficient holding force. Flow cup (17) according to one of the preceding claims, characterized in that the fluid-tight seal between the lid arrangement (20) and material container (19) when using the flow cup (17) with an inner bag (18) by an axial and/or radial seal and during use of the flow cup (17) without an inner bag (18) by means of an axial and/or radial seal. Gravity cup (17) according to one of the preceding claims, characterized in that the connection between the cover arrangement (20) and material container (19) is designed in such a way that the cover arrangement (20) and the material container (19) are connected to one another in a fluid-tight manner in a first position , when the inner bag (18) is clamped between them, and fluid-tightly connected to each other in a second position, when no inner bag (18) is clamped between them. Flow cup (17) according to one of the preceding claims, characterized in that the connection (26) between the lid arrangement (20) and material container (19) is designed in such a way that when the flow cup (17) with inner bag (18) is used, the inner bag (18 ) is clamped in a radial annular gap between the lid arrangement (20) and the material container (19), the lid arrangement (20) and the material container (19) being directly radially adjacent to one another in the region of the radial annular gap when the flow cup (17) is used without an inner bag (18). abut or are spaced apart. Flow cup (17) according to one of the preceding claims, characterized in that the connection (26) between the lid arrangement (20) and material container (19) is designed in such a way that when the flow cup (17) with inner bag (18) is used, the inner bag (18 ), in particular an edge (21) of the inner bag (18), is clamped in an axial annular gap between the lid arrangement (20) and the material container (19), the lid arrangement (20) and the material container (19) when the flow cup (17) is used without an inner bag (18) in the area of the axial annular gap directly abut one another axially or are spaced apart from one another. Gravity cup (17) according to any one of the preceding claims, characterized in that the Lid arrangement (20) is provided with a receiving groove (43) for an edge region of the material container (19), with a central region (30) of the lid arrangement (20), which adjoins the receiving groove (43), preferably as a continuation of at least a major part of a Inner leg of the receiving groove (43) is performed. Gravity cup (17) according to one of the preceding claims, characterized in that the cover arrangement (20) is provided with a receiving groove (43) for an edge region of the material container (19), which is adjoined radially on the inside by a compensating ring groove (45). Gravity cup (17) according to one of the preceding claims, characterized in that the connection (26) between the cover arrangement (20) and material container (19) is designed as a screw connection (26), in particular as a multi-threaded screw connection (26). Inner bag (18) for a gravity cup (17), in particular according to one of the preceding claims, characterized in that the inner bag (18) has a peripheral edge (21) on an open end face, from which a peripheral wall (22) leads away, which preferably is closed on the opposite end or has an outlet extension (23). Inner bag (18) after Claim 14 , characterized in that the inner bag (18) is made of plastic in a deep-drawing process. Inner bag (18) according to one of Claims 14 or 15 , characterized in that the inner bag (18) is provided with at least one fold line (46), due to which the inner bag (18) contracts due to a negative pressure inside or due to the coating material escaping from its interior with reduced pressure and/or reduced residual volume. Inner bag (18) according to one of Claims 14 until 16 , characterized in that the inner bag (18) is provided with at least one fold line (46) which results from the shaping and/or weakening of the bag wall (22) along the fold line (46). Inner bag (18) according to one of Claims 14 until 17 , characterized in that the inner bag (18) is provided with at least one fold line (46) which runs closed in the form of a ring or in a spiral on the peripheral wall (22) of the inner bag (18). Inner bag (18) according to one of Claims 14 until 18 , characterized in that the inner bag (18) is provided with a plurality of ring-shaped closed fold lines (46) which are at equal distances from one another or have increasing or decreasing distances in the longitudinal direction of the inner bag (18). Inner bag (18) according to one of Claims 14 until 19 , characterized in that the inner bag (18) is designed like a bellows. Inner bag according to one of Claims 14 until 20 , characterized in that the inner bag (18) opposite to the open end is closed with a smooth bottom (39) or is provided with a funnel-like outlet extension (23). Flow cup arrangement (11) with a flow cup (17) according to one of Claims 1 until 13 and an inner bag (18) according to any one of Claims 14 until 21 . Gravity cup arrangement (11) after Claim 22 , characterized in that the flow cup arrangement (11) comprises a replacement element (27), in particular an annular sealing element (27), which can be clamped between the lid arrangement (20) and material container (19) instead of the inner bag (18) in order to Use the flow cup (17) without the inner bag (18).

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